diff --git a/python/mozbuild/mozbuild/backend/android_eclipse.py b/python/mozbuild/mozbuild/backend/android_eclipse.py
index 97508d137872..a1bd995c1dff 100644
--- a/python/mozbuild/mozbuild/backend/android_eclipse.py
+++ b/python/mozbuild/mozbuild/backend/android_eclipse.py
@@ -24,6 +24,7 @@ from ..frontend.data import (
 )
 from ..makeutil import Makefile
 from ..util import ensureParentDir
+from mozbuild.base import ExecutionSummary
 
 
 def pretty_print(element):
@@ -38,22 +39,17 @@ class AndroidEclipseBackend(CommonBackend):
     """Backend that generates Android Eclipse project files.
     """
 
-    def _init(self):
-        CommonBackend._init(self)
-
-        def detailed(summary):
-            s = 'Wrote {:d} Android Eclipse projects to {:s}; ' \
-                '{:d} created; {:d} updated'.format(
-                summary.created_count + summary.updated_count,
-                mozpath.join(self.environment.topobjdir, 'android_eclipse'),
-                summary.created_count,
-                summary.updated_count)
-
-            return s
-
-        # This is a little kludgy and could be improved with a better API.
-        self.summary.backend_detailed_summary = types.MethodType(detailed,
-            self.summary)
+    def summary(self):
+        return ExecutionSummary(
+            'AndroidEclipse backend executed in {execution_time:.2f}s\n'
+            'Wrote {projects:d} Android Eclipse projects to {path:s}; '
+            '{created:d} created; {updated:d} updated',
+            execution_time=self._execution_time,
+            projects=self._created_count + self._updated_count,
+            path=mozpath.join(self.environment.topobjdir, 'android_eclipse'),
+            created=self._created_count,
+            updated=self._updated_count,
+        )
 
     def consume_object(self, obj):
         """Write out Android Eclipse project files."""
@@ -257,7 +253,7 @@ class AndroidEclipseBackend(CommonBackend):
 
         # When we re-create the build backend, we kill everything that was there.
         if os.path.isdir(project_directory):
-            self.summary.updated_count += 1
+            self._updated_count += 1
         else:
-            self.summary.created_count += 1
+            self._created_count += 1
         copier.copy(project_directory, skip_if_older=False, remove_unaccounted=True)
diff --git a/python/mozbuild/mozbuild/backend/base.py b/python/mozbuild/mozbuild/backend/base.py
index 5c67572d6617..0096409392c1 100644
--- a/python/mozbuild/mozbuild/backend/base.py
+++ b/python/mozbuild/mozbuild/backend/base.py
@@ -21,102 +21,9 @@ import mozpack.path as mozpath
 from ..preprocessor import Preprocessor
 from ..pythonutil import iter_modules_in_path
 from ..util import FileAvoidWrite
-from ..frontend.data import (
-    ContextDerived,
-    ReaderSummary,
-)
+from ..frontend.data import ContextDerived
 from .configenvironment import ConfigEnvironment
-
-
-class BackendConsumeSummary(object):
-    """Holds state about what a backend did.
-
-    This is used primarily to print a summary of what the backend did
-    so people know what's going on.
-    """
-    def __init__(self):
-        # How many moz.build files were read. This includes included files.
-        self.mozbuild_count = 0
-
-        # The number of derived objects from the read moz.build files.
-        self.object_count = 0
-
-        # The number of backend files created.
-        self.created_count = 0
-
-        # The number of backend files updated.
-        self.updated_count = 0
-
-        # The number of unchanged backend files.
-        self.unchanged_count = 0
-
-        # The number of deleted backend files.
-        self.deleted_count = 0
-
-        # The total wall time this backend spent consuming objects. If
-        # the iterable passed into consume() is a generator, this includes the
-        # time spent to read moz.build files.
-        self.wall_time = 0.0
-
-        # CPU time spent by during the interval captured by wall_time.
-        self.cpu_time = 0.0
-
-        # The total wall time spent executing moz.build files. This is just
-        # the read and execute time. It does not cover consume time.
-        self.mozbuild_execution_time = 0.0
-
-        # The total wall time spent emitting objects from sandboxes.
-        self.emitter_execution_time = 0.0
-
-        # The total wall time spent in the backend. This counts the time the
-        # backend writes out files, etc.
-        self.backend_execution_time = 0.0
-
-        # How much wall time the system spent doing other things. This is
-        # wall_time - mozbuild_execution_time - emitter_execution_time -
-        # backend_execution_time.
-        self.other_time = 0.0
-
-        # Mapping of changed file paths to diffs of the changes.
-        self.file_diffs = {}
-
-    @property
-    def reader_summary(self):
-        return 'Finished reading {:d} moz.build files in {:.2f}s'.format(
-            self.mozbuild_count,
-            self.mozbuild_execution_time)
-
-    @property
-    def emitter_summary(self):
-        return 'Processed into {:d} build config descriptors in {:.2f}s'.format(
-            self.object_count, self.emitter_execution_time)
-
-    @property
-    def backend_summary(self):
-        return 'Backend executed in {:.2f}s'.format(self.backend_execution_time)
-
-    def backend_detailed_summary(self):
-        """Backend summary to be supplied by BuildBackend implementations."""
-        return None
-
-    @property
-    def total_summary(self):
-        efficiency_value = self.cpu_time / self.wall_time if self.wall_time else 100
-        return 'Total wall time: {:.2f}s; CPU time: {:.2f}s; Efficiency: ' \
-            '{:.0%}; Untracked: {:.2f}s'.format(
-                self.wall_time, self.cpu_time, efficiency_value,
-                self.other_time)
-
-    def summaries(self):
-        yield self.reader_summary
-        yield self.emitter_summary
-        yield self.backend_summary
-
-        detailed = self.backend_detailed_summary()
-        if detailed:
-            yield detailed
-
-        yield self.total_summary
+from mozbuild.base import ExecutionSummary
 
 
 class BuildBackend(LoggingMixin):
@@ -135,7 +42,6 @@ class BuildBackend(LoggingMixin):
         self.populate_logger()
 
         self.environment = environment
-        self.summary = BackendConsumeSummary()
 
         # Files whose modification should cause a new read and backend
         # generation.
@@ -155,8 +61,44 @@ class BuildBackend(LoggingMixin):
         self._environments = {}
         self._environments[environment.topobjdir] = environment
 
+        # The number of backend files created.
+        self._created_count = 0
+
+        # The number of backend files updated.
+        self._updated_count = 0
+
+        # The number of unchanged backend files.
+        self._unchanged_count = 0
+
+        # The number of deleted backend files.
+        self._deleted_count = 0
+
+        # The total wall time spent in the backend. This counts the time the
+        # backend writes out files, etc.
+        self._execution_time = 0.0
+
+        # Mapping of changed file paths to diffs of the changes.
+        self.file_diffs = {}
+
         self._init()
 
+    def summary(self):
+        return ExecutionSummary(
+            self.__class__.__name__.replace('Backend', '') +
+            ' backend executed in {execution_time:.2f}s\n  '
+            '{total:d} total backend files; '
+            '{created:d} created; '
+            '{updated:d} updated; '
+            '{unchanged:d} unchanged; '
+            '{deleted:d} deleted',
+            execution_time=self._execution_time,
+            total=self._created_count + self._updated_count +
+            self._unchanged_count,
+            created=self._created_count,
+            updated=self._updated_count,
+            unchanged=self._unchanged_count,
+            deleted=self._deleted_count)
+
     def _init():
         """Hook point for child classes to perform actions during __init__.
 
@@ -173,24 +115,14 @@ class BuildBackend(LoggingMixin):
         base class consumes objects and calls methods (possibly) implemented by
         child classes.
         """
-        cpu_start = time.clock()
-        time_start = time.time()
-        backend_time = 0.0
-
         for obj in objs:
-            self.summary.object_count += 1
             obj_start = time.time()
             self.consume_object(obj)
-            backend_time += time.time() - obj_start
+            self._execution_time += time.time() - obj_start
 
             if isinstance(obj, ContextDerived):
                 self.backend_input_files |= obj.context_all_paths
 
-            if isinstance(obj, ReaderSummary):
-                self.summary.mozbuild_count = obj.total_file_count
-                self.summary.mozbuild_execution_time = obj.total_sandbox_execution_time
-                self.summary.emitter_execution_time = obj.total_emitter_execution_time
-
         # Pull in all loaded Python as dependencies so any Python changes that
         # could influence our output result in a rescan.
         self.backend_input_files |= set(iter_modules_in_path(
@@ -198,14 +130,14 @@ class BuildBackend(LoggingMixin):
 
         finished_start = time.time()
         self.consume_finished()
-        backend_time += time.time() - finished_start
+        self._execution_time += time.time() - finished_start
 
         # Purge backend files created in previous run, but not created anymore
         delete_files = self._backend_output_list - self._backend_output_files
         for path in delete_files:
             try:
                 os.unlink(mozpath.join(self.environment.topobjdir, path))
-                self.summary.deleted_count += 1
+                self._deleted_count += 1
             except OSError:
                 pass
         # Remove now empty directories
@@ -216,24 +148,14 @@ class BuildBackend(LoggingMixin):
                 pass
 
         # Write out the list of backend files generated, if it changed.
-        if self.summary.deleted_count or self.summary.created_count or \
+        if self._deleted_count or self._created_count or \
                 not os.path.exists(self._backend_output_list_file):
             with open(self._backend_output_list_file, 'w') as fh:
                 fh.write('\n'.join(sorted(self._backend_output_files)))
-        elif self.summary.updated_count:
+        elif self._updated_count:
             with open(self._backend_output_list_file, 'a'):
                 os.utime(self._backend_output_list_file, None)
 
-        self.summary.cpu_time = time.clock() - cpu_start
-        self.summary.wall_time = time.time() - time_start
-        self.summary.backend_execution_time = backend_time
-        self.summary.other_time = self.summary.wall_time - \
-            self.summary.mozbuild_execution_time - \
-            self.summary.emitter_execution_time - \
-            self.summary.backend_execution_time
-
-        return self.summary
-
     @abstractmethod
     def consume_object(self, obj):
         """Consumes an individual TreeMetadata instance.
@@ -250,7 +172,7 @@ class BuildBackend(LoggingMixin):
         """Context manager to write a file.
 
         This is a glorified wrapper around FileAvoidWrite with integration to
-        update the BackendConsumeSummary on this instance.
+        update the summary data on this instance.
 
         Example usage:
 
@@ -276,13 +198,13 @@ class BuildBackend(LoggingMixin):
         self._backend_output_files.add(mozpath.relpath(fh.name, self.environment.topobjdir))
         existed, updated = fh.close()
         if not existed:
-            self.summary.created_count += 1
+            self._created_count += 1
         elif updated:
-            self.summary.updated_count += 1
+            self._updated_count += 1
             if fh.diff:
-                self.summary.file_diffs[fh.name] = fh.diff
+                self.file_diffs[fh.name] = fh.diff
         else:
-            self.summary.unchanged_count += 1
+            self._unchanged_count += 1
 
     @contextmanager
     def _get_preprocessor(self, obj):
diff --git a/python/mozbuild/mozbuild/backend/cpp_eclipse.py b/python/mozbuild/mozbuild/backend/cpp_eclipse.py
index a7b4a5548d79..50897a0a39ab 100644
--- a/python/mozbuild/mozbuild/backend/cpp_eclipse.py
+++ b/python/mozbuild/mozbuild/backend/cpp_eclipse.py
@@ -15,6 +15,7 @@ from .common import CommonBackend
 from ..frontend.data import (
     Defines,
 )
+from mozbuild.base import ExecutionSummary
 
 # TODO Have ./mach eclipse generate the workspace and index it:
 # /Users/bgirard/mozilla/eclipse/eclipse/eclipse/eclipse -application org.eclipse.cdt.managedbuilder.core.headlessbuild -data $PWD/workspace -importAll $PWD/eclipse
@@ -41,15 +42,15 @@ class CppEclipseBackend(CommonBackend):
         # Note: We need the C Pre Processor (CPP) flags, not the CXX flags
         self._cppflags = self.environment.substs.get('CPPFLAGS', '')
 
-        def detailed(summary):
-            return ('Generated Cpp Eclipse workspace in "%s".\n' + \
-                   'If missing, import the project using File > Import > General > Existing Project into workspace\n' + \
-                   '\n' + \
-                   'Run with: eclipse -data %s\n') \
-                   % (self._workspace_dir, self._workspace_dir)
-
-        self.summary.backend_detailed_summary = types.MethodType(detailed,
-            self.summary)
+    def summary(self):
+        return ExecutionSummary(
+            'CppEclipse backend executed in {execution_time:.2f}s\n'
+            'Generated Cpp Eclipse workspace in "{workspace:s}".\n'
+            'If missing, import the project using File > Import > General > Existing Project into workspace\n'
+            '\n'
+            'Run with: eclipse -data {workspace:s}\n',
+            execution_time=self._execution_time,
+            workspace=self._workspace_dir)
 
     def _get_workspace_path(self):
         return CppEclipseBackend.get_workspace_path(self.environment.topsrcdir, self.environment.topobjdir)
diff --git a/python/mozbuild/mozbuild/backend/recursivemake.py b/python/mozbuild/mozbuild/backend/recursivemake.py
index d2e8daa743cf..3ed7ebf1e76f 100644
--- a/python/mozbuild/mozbuild/backend/recursivemake.py
+++ b/python/mozbuild/mozbuild/backend/recursivemake.py
@@ -376,26 +376,8 @@ class RecursiveMakeBackend(CommonBackend):
         self._backend_files = {}
         self._idl_dirs = set()
 
-        def detailed(summary):
-            s = '{:d} total backend files; ' \
-                '{:d} created; {:d} updated; {:d} unchanged; ' \
-                '{:d} deleted; {:d} -> {:d} Makefile'.format(
-                summary.created_count + summary.updated_count +
-                summary.unchanged_count,
-                summary.created_count,
-                summary.updated_count,
-                summary.unchanged_count,
-                summary.deleted_count,
-                summary.makefile_in_count,
-                summary.makefile_out_count)
-
-            return s
-
-        # This is a little kludgy and could be improved with a better API.
-        self.summary.backend_detailed_summary = types.MethodType(detailed,
-            self.summary)
-        self.summary.makefile_in_count = 0
-        self.summary.makefile_out_count = 0
+        self._makefile_in_count = 0
+        self._makefile_out_count = 0
 
         self._test_manifests = {}
 
@@ -428,6 +410,13 @@ class RecursiveMakeBackend(CommonBackend):
             'tools': set(),
         }
 
+    def summary(self):
+        summary = super(RecursiveMakeBackend, self).summary()
+        summary.extend('; {makefile_in:d} -> {makefile_out:d} Makefile',
+                       makefile_in=self._makefile_in_count,
+                       makefile_out=self._makefile_out_count)
+        return summary
+
     def _get_backend_file_for(self, obj):
         if obj.objdir not in self._backend_files:
             self._backend_files[obj.objdir] = \
@@ -802,7 +791,7 @@ class RecursiveMakeBackend(CommonBackend):
                 if not stub:
                     self.log(logging.DEBUG, 'substitute_makefile',
                         {'path': makefile}, 'Substituting makefile: {path}')
-                    self.summary.makefile_in_count += 1
+                    self._makefile_in_count += 1
 
                     for tier, skiplist in self._may_skip.items():
                         if bf.relobjdir in skiplist:
@@ -1451,7 +1440,7 @@ INSTALL_TARGETS += %(prefix)s
             # the autogenerated one automatically.
             self.backend_input_files.add(obj.input_path)
 
-        self.summary.makefile_out_count += 1
+        self._makefile_out_count += 1
 
     def _handle_ipdl_sources(self, ipdl_dir, sorted_ipdl_sources,
                              unified_ipdl_cppsrcs_mapping):
diff --git a/python/mozbuild/mozbuild/backend/visualstudio.py b/python/mozbuild/mozbuild/backend/visualstudio.py
index 05865305c125..4cca70a2d5c3 100644
--- a/python/mozbuild/mozbuild/backend/visualstudio.py
+++ b/python/mozbuild/mozbuild/backend/visualstudio.py
@@ -27,6 +27,7 @@ from ..frontend.data import (
     Sources,
     UnifiedSources,
 )
+from mozbuild.base import ExecutionSummary
 
 
 MSBUILD_NAMESPACE = 'http://schemas.microsoft.com/developer/msbuild/2003'
@@ -101,12 +102,12 @@ class VisualStudioBackend(CommonBackend):
         self._paths_to_configs = {}
         self._libs_to_paths = {}
 
-        def detailed(summary):
-            return 'Generated Visual Studio solution at %s' % (
-                os.path.join(self._out_dir, 'mozilla.sln'))
-
-        self.summary.backend_detailed_summary = types.MethodType(detailed,
-            self.summary)
+    def summary(self):
+        return ExecutionSummary(
+            'VisualStudio backend executed in {execution_time:.2f}s\n'
+            'Generated Visual Studio solution at {path:s}',
+            execution_time=self._execution_time,
+            path=os.path.join(self._out_dir, 'mozilla.sln'))
 
     def consume_object(self, obj):
         # Just acknowledge everything.
diff --git a/python/mozbuild/mozbuild/base.py b/python/mozbuild/mozbuild/base.py
index 8b4ea73f5db7..3a1bb9caee49 100644
--- a/python/mozbuild/mozbuild/base.py
+++ b/python/mozbuild/mozbuild/base.py
@@ -843,3 +843,22 @@ class PathArgument(object):
 
     def objdir_path(self):
         return mozpath.join(self.topobjdir, self.relpath())
+
+
+class ExecutionSummary(dict):
+    """Helper for execution summaries."""
+
+    def __init__(self, summary_format, **data):
+        self._summary_format = ''
+        assert 'execution_time' in data
+        self.extend(summary_format, **data)
+
+    def extend(self, summary_format, **data):
+        self._summary_format += summary_format
+        self.update(data)
+
+    def __str__(self):
+        return self._summary_format.format(**self)
+
+    def __getattr__(self, key):
+        return self[key]
diff --git a/python/mozbuild/mozbuild/config_status.py b/python/mozbuild/mozbuild/config_status.py
index 49b00fa922e6..465fd142fbfc 100644
--- a/python/mozbuild/mozbuild/config_status.py
+++ b/python/mozbuild/mozbuild/config_status.py
@@ -11,6 +11,7 @@ from __future__ import absolute_import, print_function
 import logging
 import os
 import sys
+import time
 
 from optparse import OptionParser
 
@@ -133,6 +134,9 @@ def config_status(topobjdir='.', topsrcdir='.',
         from mozbuild.backend.fastermake import FasterMakeBackend
         backend_cls = FasterMakeBackend
 
+    cpu_start = time.clock()
+    time_start = time.time()
+
     the_backend = backend_cls(env)
 
     reader = BuildReader(env)
@@ -150,13 +154,28 @@ def config_status(topobjdir='.', topsrcdir='.',
     log_manager.enable_unstructured()
 
     print('Reticulating splines...', file=sys.stderr)
-    summary = the_backend.consume(definitions)
+    the_backend.consume(definitions)
 
-    for line in summary.summaries():
-        print(line, file=sys.stderr)
+    execution_time = 0.0
+    for obj in (reader, emitter, the_backend):
+        summary = obj.summary()
+        print(summary, file=sys.stderr)
+        execution_time += summary.execution_time
+
+    cpu_time = time.clock() - cpu_start
+    wall_time = time.time() - time_start
+    efficiency = cpu_time / wall_time if wall_time else 100
+    untracked = wall_time - execution_time
+
+    print(
+        'Total wall time: {:.2f}s; CPU time: {:.2f}s; Efficiency: '
+        '{:.0%}; Untracked: {:.2f}s'.format(
+            wall_time, cpu_time, efficiency, untracked),
+        file=sys.stderr
+    )
 
     if options.diff:
-        for path, diff in sorted(summary.file_diffs.items()):
+        for path, diff in sorted(the_backend.file_diffs.items()):
             print('\n'.join(diff))
 
     # Advertise Visual Studio if appropriate.
diff --git a/python/mozbuild/mozbuild/frontend/context.py b/python/mozbuild/mozbuild/frontend/context.py
index e8c8d80c841f..b89f5c35c5a8 100644
--- a/python/mozbuild/mozbuild/frontend/context.py
+++ b/python/mozbuild/mozbuild/frontend/context.py
@@ -88,7 +88,6 @@ class Context(KeyedDefaultDict):
         # a list to be a problem.
         self._all_paths = []
         self.config = config
-        self.execution_time = 0
         self._sandbox = None
         KeyedDefaultDict.__init__(self, self._factory)
 
diff --git a/python/mozbuild/mozbuild/frontend/data.py b/python/mozbuild/mozbuild/frontend/data.py
index 1448b76bb898..fca98864e9a1 100644
--- a/python/mozbuild/mozbuild/frontend/data.py
+++ b/python/mozbuild/mozbuild/frontend/data.py
@@ -43,17 +43,6 @@ class TreeMetadata(object):
         self._ack = True
 
 
-class ReaderSummary(TreeMetadata):
-    """A summary of what the reader did."""
-
-    def __init__(self, total_file_count, total_sandbox_execution_time,
-        total_emitter_execution_time):
-        TreeMetadata.__init__(self)
-        self.total_file_count = total_file_count
-        self.total_sandbox_execution_time = total_sandbox_execution_time
-        self.total_emitter_execution_time = total_emitter_execution_time
-
-
 class ContextDerived(TreeMetadata):
     """Build object derived from a single Context instance.
 
diff --git a/python/mozbuild/mozbuild/frontend/emitter.py b/python/mozbuild/mozbuild/frontend/emitter.py
index 1baa9b30da47..0e818abe73e8 100644
--- a/python/mozbuild/mozbuild/frontend/emitter.py
+++ b/python/mozbuild/mozbuild/frontend/emitter.py
@@ -63,7 +63,6 @@ from .data import (
     PreprocessedTestWebIDLFile,
     PreprocessedWebIDLFile,
     Program,
-    ReaderSummary,
     Resources,
     SharedLibrary,
     SimpleProgram,
@@ -95,6 +94,8 @@ from .context import (
     TemplateContext,
 )
 
+from mozbuild.base import ExecutionSummary
+
 
 class TreeMetadataEmitter(LoggingMixin):
     """Converts the executed mozbuild files into data structures.
@@ -136,19 +137,27 @@ class TreeMetadataEmitter(LoggingMixin):
         # Add security/nss manually, since it doesn't have a subconfigure.
         self._external_paths.add('security/nss')
 
+        self._emitter_time = 0.0
+        self._object_count = 0
+
+    def summary(self):
+        return ExecutionSummary(
+            'Processed into {object_count:d} build config descriptors in '
+            '{execution_time:.2f}s',
+            execution_time=self._emitter_time,
+            object_count=self._object_count)
+
     def emit(self, output):
         """Convert the BuildReader output into data structures.
 
         The return value from BuildReader.read_topsrcdir() (a generator) is
         typically fed into this function.
         """
-        file_count = 0
-        sandbox_execution_time = 0.0
-        emitter_time = 0.0
         contexts = {}
 
         def emit_objs(objs):
             for o in objs:
+                self._object_count += 1
                 yield o
                 if not o._ack:
                     raise Exception('Unhandled object of type %s' % type(o))
@@ -166,14 +175,10 @@ class TreeMetadataEmitter(LoggingMixin):
                 start = time.time()
                 # We need to expand the generator for the timings to work.
                 objs = list(self.emit_from_context(out))
-                emitter_time += time.time() - start
+                self._emitter_time += time.time() - start
 
                 for o in emit_objs(objs): yield o
 
-                # Update the stats.
-                file_count += len(out.all_paths)
-                sandbox_execution_time += out.execution_time
-
             else:
                 raise Exception('Unhandled output type: %s' % type(out))
 
@@ -182,12 +187,10 @@ class TreeMetadataEmitter(LoggingMixin):
         if self.config.substs.get('COMPILE_ENVIRONMENT', True):
             start = time.time()
             objs = list(self._emit_libs_derived(contexts))
-            emitter_time += time.time() - start
+            self._emitter_time += time.time() - start
 
             for o in emit_objs(objs): yield o
 
-        yield ReaderSummary(file_count, sandbox_execution_time, emitter_time)
-
     def _emit_libs_derived(self, contexts):
         # First do FINAL_LIBRARY linkage.
         for lib in (l for libs in self._libs.values() for l in libs):
diff --git a/python/mozbuild/mozbuild/frontend/gyp_reader.py b/python/mozbuild/mozbuild/frontend/gyp_reader.py
index 1346a66e8173..4b29ba6a6281 100644
--- a/python/mozbuild/mozbuild/frontend/gyp_reader.py
+++ b/python/mozbuild/mozbuild/frontend/gyp_reader.py
@@ -6,7 +6,6 @@ from __future__ import absolute_import, unicode_literals
 
 import gyp
 import sys
-import time
 import os
 import mozpack.path as mozpath
 from mozpack.files import FileFinder
@@ -83,8 +82,6 @@ def read_from_gyp(config, path, output, vars, non_unified_sources = set()):
     processor.
     """
 
-    time_start = time.time()
-
     # gyp expects plain str instead of unicode. The frontend code gives us
     # unicode strings, so convert them.
     path = encode(path)
@@ -234,6 +231,4 @@ def read_from_gyp(config, path, output, vars, non_unified_sources = set()):
             context['DEFINES']['_UNICODE'] = True
         context['DISABLE_STL_WRAPPING'] = True
 
-        context.execution_time = time.time() - time_start
         yield context
-        time_start = time.time()
diff --git a/python/mozbuild/mozbuild/frontend/reader.py b/python/mozbuild/mozbuild/frontend/reader.py
index 0b2d0044a3ef..4eb597d3b634 100644
--- a/python/mozbuild/mozbuild/frontend/reader.py
+++ b/python/mozbuild/mozbuild/frontend/reader.py
@@ -78,6 +78,9 @@ from .context import (
     TemplateContext,
 )
 
+from mozbuild.base import ExecutionSummary
+
+
 if sys.version_info.major == 2:
     text_type = unicode
     type_type = types.TypeType
@@ -869,6 +872,16 @@ class BuildReader(object):
         self._execution_stack = []
         self._finder = finder
 
+        self._execution_time = 0.0
+        self._file_count = 0
+
+    def summary(self):
+        return ExecutionSummary(
+            'Finished reading {file_count:d} moz.build files in '
+            '{execution_time:.2f}s',
+            file_count=self._file_count,
+            execution_time=self._execution_time)
+
     def read_topsrcdir(self):
         """Read the tree of linked moz.build files.
 
@@ -1103,7 +1116,8 @@ class BuildReader(object):
         sandbox = MozbuildSandbox(context, metadata=metadata,
                                   finder=self._finder)
         sandbox.exec_file(path)
-        context.execution_time = time.time() - time_start
+        self._execution_time += time.time() - time_start
+        self._file_count += len(context.all_paths)
 
         # Yield main context before doing any processing. This gives immediate
         # consumers an opportunity to change state before our remaining
@@ -1141,6 +1155,7 @@ class BuildReader(object):
                     raise SandboxValidationError('Cannot find %s.' % source,
                         context)
                 non_unified_sources.add(source)
+            time_start = time.time()
             for gyp_context in read_from_gyp(context.config,
                                              mozpath.join(curdir, gyp_dir.input),
                                              mozpath.join(context.objdir,
@@ -1149,6 +1164,8 @@ class BuildReader(object):
                                              non_unified_sources = non_unified_sources):
                 gyp_context.update(gyp_dir.sandbox_vars)
                 gyp_contexts.append(gyp_context)
+                self._file_count += len(gyp_context.all_paths)
+            self._execution_time += time.time() - time_start
 
         for gyp_context in gyp_contexts:
             context['DIRS'].append(mozpath.relpath(gyp_context.objdir, context.objdir))
diff --git a/python/mozbuild/mozbuild/test/frontend/test_emitter.py b/python/mozbuild/mozbuild/test/frontend/test_emitter.py
index c7ce9768092b..7a9ede60a082 100644
--- a/python/mozbuild/mozbuild/test/frontend/test_emitter.py
+++ b/python/mozbuild/mozbuild/test/frontend/test_emitter.py
@@ -27,7 +27,6 @@ from mozbuild.frontend.data import (
     JsPreferenceFile,
     LocalInclude,
     Program,
-    ReaderSummary,
     Resources,
     SimpleProgram,
     Sources,
@@ -79,17 +78,12 @@ class TestEmitterBasic(unittest.TestCase):
 
         objs = list(ack(o) for o in emitter.emit(reader.read_topsrcdir()))
         self.assertGreater(len(objs), 0)
-        self.assertIsInstance(objs[-1], ReaderSummary)
 
         filtered = []
         for obj in objs:
             if filter_common and isinstance(obj, DirectoryTraversal):
                 continue
 
-            # Always filter ReaderSummary because it's asserted above.
-            if isinstance(obj, ReaderSummary):
-                continue
-
             filtered.append(obj)
 
         return filtered